The objective of this study was to describe situations related to sexual health of adolescents, according to the National Survey of School Health (PeNSE). It is a cross-sectional study performed by the Brazilian Institute of Geography and Statistics (IBGE), in partnership with the Ministry of Health that involved 60,973 students and 1,453 public and private schools. Data analysis points out that 30.5% (95%CI 29.9-31.2) of the adolescents had already had sexual relations sometime in their lives, being more frequent for males (43.7%; 95%CI 42.7-44.7) than females (18.7%; 95%CI 18.0-19.4), especially those who go to public schools (33.1%; 95%CI 32.4-33.9), aged 15 years or older (47.3%; 95%CI 45.7-48.9) and 16 years (63.5%; 95%CI 61,5-65.4). The sexual initiation age was early and 40.1% (95%CI 38.8-41.4) reported having had only one partner in life. The use of condoms in the last sexual relation was high both for protective (75.9%; CI95% 74.8-76.9) and contraceptive methods (74.7%; 95%CI 73.6-75.7). It is necessary to emphasize actions for promoting sexual health towards adolescents in order to minimize vulnerabilities.